Bug ID 626068: Memory Requirement for deploying Bot Signatures in DoS profiles

Last Modified: Jan 29, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP ASM(all modules)

Known Affected Versions:
13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4

Opened: Nov 01, 2016
Severity: 4-Minor

Symptoms

When deploying large number of DoS profiles with Bot signatures enabled on low-end platforms, the memory spills over to the swap area. Each DoS profile consumes about 2 MB of memory per core for accommodating the complied bot signatures. For example, on VE with 2 cores and 8 GB of memory, deploying 1024 DoS profiles with bot signatures will consume 4 GB which together with the other memory requirements of ASM far exceeds the physical memory. The symptom is high utilization of swap memory.

Impact

Severe performance degradation.

Conditions

Deploy large number (over 100) of DoS profiles with Bot signatures.

Workaround

On VE platforms, provision at least 4 GB more memory to the VM. On vCMP platform, assign this amount of memory to the guest machine. On physical machines, the only option is to upgrade to a larger memory platform. Consider using less profiles by reusing the same DoS profile on more than one Virtual Server.

Fix Information

None

Behavior Change